The prior patent art contains a large number of zone controlled deflection compensated rolls of the type in which an outer sleeve rotates about, and is supported on a stationary or non-rotating central support beam. A plurality of hydrostatic support elements are positioned along the beam and move or apply a force against an inside surface of the sleeve. While these prior roll concepts are adequate to control the deflection of the sleeve so as to provide a straight line nip or assure a uniform pressure along the nip, as desired, they are generally complex mechanisms and are costly to make and to maintain.
It has also been recognized that for optimum control of the force exerted against the inside of the sleeve, the force applying member or shoe must have certain freedoms of movement, and must provide a contacting surface which is capable of applying or transmitting substantial forces to the shell over long periods of time. Hydrostatic force members which have been designed to meet these requirements have been characterized by complexity of the hydrostatic pressure members and of the supporting structure.
A need exists for an effective, simplified and lower priced controlled deflection roll which has components which are not critical to make and which are easy to maintain, and which operate on the principles of hydrodynamics.
In addition to the complications in the hydrostatic control and structure of the roll, the roll drive mechanisms themselves have been complicated by reason having to absorb or allow for sleeve angular deflections. This has given rise to a need for a more effective, efficient, and simplified roll drive for compensated deflection roll systems.